The third international conference on Microbial Pathogenesis and Host Response will focus on interdisciplinary approaches to study infectious disease, integrating the disciplines of molecular microbiology, eukaryotic cell biology, immunology, and genomics. Microbial diseases have once again taken an important central role in health care worldwide, due to the emergence of new pathogens and the re-ascent of common pathogens. In particular, the greatly increased emphasis on developing strategies to prevent bioterrorism has also influenced the selection of speakers for the meeting. The meeting will provide an in depth focus on the approaches that are being used to elucidate the mechanisms of bacterial and fungal pathogenesis, and promote the application of these concepts to novel strategies for the control and intervention of infectious diseases. Oral and poster sessions will focus on major themes of microbial pathogenesis and the host response: how microbes adhere to host cells; how microbial pathogenesis is influenced by environmental cues; how microbial pathogens modulate host cells; how host cells respond to microbial pathogens; how the host immune system reacts to microbial pathogens; how microbial pathogens evolve; and how emerging pathogens take advantage of new ecological niches. The sessions will integrate studies on bacterial and fungal pathogens. The oral sessions will begin with 2-4 invited talks by established leaders in the field, followed by several shorter talks chosen from submitted abstracts. The inclusion of two poster sessions as well as the allotment of ample time for questions following each talk will encourage extensive discussion between the participants. The meeting will be small enough (300 - 400 scientists) to facilitate these interactions, yet large enough to allow for oral presentations not only from established investigators, but also from younger investigators and those with novel perspectives. The integration of a wide variety of aspects of bacterial and fungal pathogenesis with the host response to pathogens should promote new interdisciplinary interactions that are seldom achieved at other meetings on microbial pathogenesis that are either more narrowly focused or so diverse that the topics are difficult to integrate. The resulting interdisciplinary interactions will yield novel experimental approaches that might not otherwise be possible. The subsequent meetings (2005 and 2007) will follow a similar format and will include topics that are highly relevant at the time of the meeting.